Application handpiece with lamp of novel shape

ABSTRACT

An essentially u-shaped discharge lamp ( 13 ) comprises a gaz fill and a pair of electrodes ( 15 ) at its ends. The lamp ( 13 ) way be comprised in a handpiece ( 1 ) for treating a surface by means of electromagnetic radiation.

TECHNICAL FIELD

The present invention relates to an application handpiece and a lamp forsaid handpiece, designed for use in equipment for medical and cosmetictreatment, and also for all applications in which a flash lamp sourcewith the smallest possible lateral dimension has to be used in theproximity of the surface to be treated.

The lamp is a source of photons which, with suitable intensity andtime-based delivery control laws, can be used for action on the humanbody, for example depilation, by causing irreversible damage to thefollicle and hair bulb, or other treatments which require high densitiesof light energy on the treated surface.

BACKGROUND OF THE INVENTION

At the present time, techniques of removing excess hair are no longerapplicable solely to women with problems of hirsutism or hypertrichosis,but are commonly practiced on patients of both sexes, who are notnecessarily suffering from specific diseases, but may require treatmentfor purely cosmetic purposes. The procedures commonly used for thispurpose can be classified according to the duration of the results.According to this classification, there are short-term systems (razors,tweezers, cold and hot waxing, creams, gels and electrical depilators),and long-term systems which, after a certain number of sessions, caneven yield permanent results. Some examples of this second group ofsystems are electrocoagulation needles, radio frequency scalpel needles,non-coherent light and lasers. Among the long-term treatment methods,the greatest success has been obtained with the use of systems based onthe theory of selective photothermolysis, which cause damage to the hairbulb by means of the electromagnetic energy absorbed by the melaninpresent in the hair or by the hemoglobin of the follicle blood vessels.

Non-coherent light and laser depilation systems are more effective whenthey strike the hair in the growth phase (“anagen”). The growth of hairis not continuous, but cyclical: a rest period called “telogen” followseach growth period called “anagen”; the transition period between thetwo phases is known as “catagen”. The duration of the cycle is differentin the different regions, varying from 2–6 years for the head hair toonly 4–8 weeks for the eyebrows. According to current biological models,the cells giving rise to the follicle are located in what is known asthe “bulge area”. These cells form the new hair matrix, thus initiatingthe growth phase. In the initial part of this phase, when the follicleis shorter, the papilla is closer to the skin surface; subsequently itincreases its length, proliferating for a period which varies accordingto the anatomical location. It is in the initial phase of anagen, oranagen 1, that the “target” structures of the follicle (such as thepapilla and the bulge area) with its vascular system are closer to thehair and to the skin surface; as the papilla and the end part of thehair become closer, there is a greater probability that the “light”energy absorbed by the melanin of the skin, and that which arrivesdirectly, will cause irreparable damage to the papilla, permanentlyblocking its ability to make a hair grow. From what has been statedabove, it is evident why the action of a “photodepilation” system ismore effective in the anagen phase.

In a non-coherent light depilation system, use is made of a dischargelamp, normally consisting of a cylindrical container of material whichis transparent to the electromagnetic radiation in the visible band andin the near infrared. Inside the container, at a suitable pressure,there is a pure gas or a mixture of gases, according to thecharacteristics to be obtained for the emitted light spectrum. At theends of the container there are two electrodes, positioned inglass-metal seals so that one end of each electrode faces the internalenvironment, where the desired gaseous atmosphere has been created,while the other end forms an externally accessible current lead for theelectrical power supply. The structure of the discharge lamp istypically rectilinear. When the lamp is excited by suitable levels ofvoltage and current, according to time-based control laws, a dischargeis initiated in the mixture contained in it, generating the emission ofthe radiation. The lamp has to be very close to the skin, or moregenerally close to the surface to be treated, in order to obtain themaximum intensity. To maximize the effectiveness of the treatment, thehandpiece must not mask any part of the surface to be treated withportions, such as the electrodes and current leads, which are not activebecause they do not emit radiation. A good illustration of this point isprovided by the depilatory application. In this case, the irradiation ofthe skin must be carried out in a uniform way, in order to avoid havinguntreated areas or areas in which treatment is repeated, especially inadjacent areas affected by two successive treatments. In other words,the operator must take great care when maneuvering the application unitcontaining the lamp, in order to provide continuity of treatment in theareas adjacent to the area concerned. It is therefore very important forthe operator to have a full view of the portion of skin or other surfaceconcerned on which the radiation is to be made to act, wherever theapplication unit is positioned.

The conventional structure of the lamps described above does not allowthe irradiated portion to be viewed satisfactorily, since theapplication handpiece has two inactive areas, namely the parts occupiedby the electrodes and by the current leads, where there is no dischargeand consequently no emission of radiation.

To overcome this problem of masking by inactive parts, applicationhandpieces have been developed with conventional lamps, in which opticalguide structures are placed in the emitting region of the lamp to guidethe light towards the surface to be treated, thus enabling the lightsource to be moved away from said surface. However, these handpieces areof complicated design, and do not fully overcome the aforementionedproblems.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to provide a lamp and anapplication handpiece which overcome the aforesaid problems in aneffective way.

These objects are achieved with a lamp as claimed in claim 1 and with ahandpiece as claimed in claim 5. Further possible advantageouscharacteristics of the handpiece and of the lamp are indicated in thedependent claims.

Essentially, according to the invention, the structure of the lamp ismodified by changing the conventional cylindrical structure with arectilinear axis to a C- or U-shaped structure, preferably with acentral portion which is still cylindrical with a rectilinear axis, butwith the two terminal portions, in which the electrodes are fitted, bentback, preferably at 90°. There is no reason why the lamp should not havea curved axis in the intermediate area, but the rectilinear form ispreferable because of its greater uniformity of irradiation and thereduction in dimensions which can be obtained.

In practice, the bending of the terminal portions can be made to startat the ends of the light-emitting discharge, in other words at the endsof the electrodes; alternatively, the bending can start in the portionin which there is still emission of light, but with a sacrifice of onlya length of each of the two terminal portions equal to the diameter ofthe structure itself, so that the discharge starts in the two bentterminal portions with the end result of a greater uniformity ofemission by the rectilinear area. In this case, the electrodes terminatebefore the area in which the terminal portions are joined to the centralrectilinear portion.

With these new types of lamp, it is possible to produce an applicationhandpiece which has a contact surface equal or approximately equal tothe area to be treated. This smaller surface is the only surface whichhas to be applied to the surface to be treated, and allows the operatorto juxtapose the treated portions accurately because of the full view ofthe operating site. The advantages of this solution over those known upto the present time, which use handpieces with rectilinear lamps, are:

-   -   a reduction in the lateral dimension and consequently the        achievement of a better view of the surface to be treated and        better handling qualities of the handpiece;    -   the reduction of the distance between the lamp and the surface        to be treated makes it possibly to shorten the light guide which        is normally provided at the window of the handpiece from which        the electromagnetic radiation is emitted;    -   the shortening of the light guide permits a reduction of        absorption losses in said guide;    -   the shortening of the light guide makes it possible to cool the        treated surface effectively by means of the lamp cooling liquid.

Furthermore, the physical dimensions of the handpiece and its weight aremuch smaller, for a given treated area, than those of other systemsbased on conventional lamps. Additionally, the light guide, being oflimited thickness, remains entirely inside the handpiece. This ensuresthat, when the lamp emits light energy, this energy remains confinedvirtually completely in the treated area, thus reducing to a minimum thelateral emission which tends to dazzle the operator, a problem thattypically arises in systems with a light guide which projects from thehandpiece.

The handpiece according to the invention comprises a pair of electricalconnections for the lamp and a housing compartment for said lamp, saidcompartment having a window for the output of the electromagneticradiation generated by said lamp. Characteristically, the electricalconnections are placed side by side and are positioned on the same sideof the housing compartment. The connections are preferably parallel toeach other, but this is not essential. The orientation of theconnections with respect to each other depends on the shape of the lamp.

The placing of the connections on the same side of the electromagneticradiation output window provides a particularly advantageousconfiguration of the handpiece, enabling the aforementioned advantagesto be obtained. In practice, the electrical connections are placed—withrespect to said housing compartment—in a position opposite said window.The position can be such that the lamp lies in a plane orthogonal to theplane of the radiation output window. However, this is not an essentialcondition, although it is preferred. This is because the lamp can alsobe positioned in a plane which is inclined with respect to the window,although the orthogonal position provides an additional reduction in theoverall dimensions of the handpiece.

The lamp is a discharge lamp and is essentially U-shaped.

In the preceding and following text, specific reference is made todepilation, but in fact the lamp and the handpiece according to theinvention have other medical and cosmetic applications (for example, thetreatment of vascular skin lesions such as port wine stain, hemangiomaand telangiectasis), in addition to applications in the industrialfield, for example in processes of drying, polymerization, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the description andthe attached drawing, which shows a practical, non-limiting example ofthe invention. In the drawing,

FIG. 1 shows a partial section through a median plane of the handpieceaccording to the invention with the lamp fitted into the handpiece, and

FIG. 2 shows a view along to II—II in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

In FIG. 1, the number 1 indicates in a general way a handpiececonstructed according to the invention. The handpiece 1 has a firstportion 3 forming the handle and a second portion 5 integral with theportion 3 and extending therefrom with a tapered shape terminating in awindow 7 filled with a light guide 9.

A compartment 11, in which a lamp 13 is housed, is formed in the taperedportion 5 of the handpiece 1. The lamp is U-shaped, with an essentiallyrectilinear and cylindrical central portion 13C, to which are joined twoterminal portions 13A and 13B, into which the electrodes 15 are fitted.These electrodes, on which a seal is made by the glass forming thecontainer that constitutes the lamp, project from the container formedby the portions 13A, 13B and 13C, to provide current leads 15A forconnection to a pair of electrical connections provided in the upperportion 3 of the handpiece 1. The electrical connections, indicatedschematically by 17, into which the current leads 15A are fitted, areparallel to each other, as are the electrodes 15, and are placed on thesame side of the compartment 11 in which the lamp is housed. However,the parallel arrangement of the connections 17 is not essential. Thelamp could also have portions 13A and 13B converging on each other, inwhich case the connections would not be parallel. Additionally, in theillustrated example the lamp is shown lying in a plane orthogonal to theplane of the light guide 9. This is the optimal configuration, but thereis no reason why the plane in which the lamp lies should not be inclinedwith respect to the light guide 9.

A reflector, indicated schematically by 21, is supported by a block 23and is positioned within the lamp housing compartment 11. The reflector21, which has a suitable shape (with a parabolic cross section, forexample), reflects the radiation generated by the discharge lamp 13towards the window filled with the light guide 9.

The block 23 is carried by a plate 25 fixed laterally to tapered lateralwalls 27. The plate 25 and the block 23 can also consist of a singlecomponent. Within the components 27 there are formed ducts 31 which openinto the compartment 11 in which the lamp is fitted, and which areconnected at their tops to tubes 33 for the introduction of a lampcooling fluid circulating in a heat dissipation system external to thehandpiece and comprising for example a heat exchanger and/or a coolingbattery. The portion 5 of the handpiece is completed and sealed with acover 29 of plastic or other material, which is carried on the front ofthe window with the light guide 9. A seal is formed around the lightguide by means of a gasket 30 between the light guide 9 and the frontedge of the walls 27, onto which the light guide is pressed. The lightguide is housed completely within the cover 29 which has a rectangularhousing forming the window for the output of the electromagneticradiation generated by the lamp 13. Thus the light radiation emitted bythe lamp does not escape laterally from the handpiece when the latter isapplied to the surface to be treated, except in wholly negligibleamounts.

A fluid, typically water, is made to circulate in the compartment 11 bymeans of the ducts 31, to remove the heat generated by the dischargelamp 13, and this can also have the function of cooling the tissue ormore generally the surface being treated. The components 27 and thecompartment [lacuna]

Annular gaskets 35 are placed above the plate 25 to prevent the escapeof cooling liquid toward the electrical connections 17.

The connections 17 are connected to electrical wires, not shown, whichpass out of the handpiece in a cord which also contains the tubes 33 forthe supply of the cooling fluid.

As clearly shown in FIG. 1, the U-shaped configuration of the lamp 13,with its central rectilinear portion 13C joined to the terminal portions13A and 13B, makes it possible to produce a handpiece having a specificshape which is tapered toward the window for the output of the radiationgenerated by the discharge lamp 13, in such a way that the operator canhave a virtually complete view of the area to be treated, and can thuscarry out more precise treatments, without either leaving areasuntreated or treating the same area twice.

The arrangement of the electrodes 15 and the corresponding electricalconnections 17 which are placed side by side, on the side opposite thewindow filled with the light guide 9, enables the light guide to be madewith a shorter length, and therefore with reduced thickness. This yieldsthe advantages indicated above.

It is to be understood that the drawing shows only an example providedsolely as a practical demonstration of the invention, this inventionbeing variable in its forms and arrangements without departure from thescope of the guiding principle of said invention.

1. A handpiece for treating a surface by means of lamp-emittedelectromagnetic radiation, comprising a grip portion for hand-grippingthe handpiece and a pair of electrical connections for a lamp and acompartment for housing said lamp, said compartment having an elongatedwindow for the output of the electromagnetic radiation generated by saidlamp, wherein: said electrical connections are placed side by side andare positioned on the same side of the housing compartment, in aposition opposite to said window, said connections being arranged atopposed ends of said windows; said compartment being designed to housean essentially U-shaped lamp having an essentially rectilinear centralportion and two terminal portions with electrodes forming current leadsby means of which said lamp is connected to said electrical connections,and said essentially rectilinear portion facing said window when thelamp is housed in said compartment, said lamp housing compartment beingclosed by said window to radiate said lamp evenly on a patient's skinsurface and a duct being provided between said compartment and saidwindow.
 2. The handpiece as claimed in claim 1, including said lamp,wherein said lamp is a flash lamp.
 3. The handpiece as claimed in claim1, wherein said window is filled with a light guide.
 4. The handpiece asclaimed in claim 3, wherein said compartment for housing in the lamp iscooled by means of a cooling fluid.
 5. The handpiece as claimed in claim1, further characterized by said grip portion and a transition portionconnected thereto, which is tapered, terminates with said output windowand houses said lamp.
 6. The handpiece as claimed in claim 4, furthercomprising: one or more ducts for the circulation of the cooling fluid,said ducts extending parallel to the tapered walls of said portionhousing said lamp.
 7. The handpiece as claimed in claim 1, wherein saidelectrical connections for the lamp are parallel to each other.
 8. Thehandpiece as claimed in claim 7, wherein said connections for the lampare orthogonal to the output window.
 9. The handpiece as claimed inclaim 1, wherein said lamp lies in a plane orthogonal to said window.10. The handpiece as claimed in claim 6, wherein said electricalconnections for the lamp are parallel to each other.
 11. The handpieceas claimed in claim 10, wherein said connections for the lamp areorthogonal to the output window.
 12. The handpiece as claimed in claim6, wherein said lamp lies in a plane orthogonal to said window.
 13. Ahandpiece for treating a surface by means of lamp-emittedelectromagnetic radiation, comprising: a pair of electrical connectionsfor the lamp and a compartment for housing a lamp, said compartmenthaving an elongated window for the output of the electromagneticradiation generated by said lamp, wherein said electrical connectionsare placed side by side and are positioned on the same side of thehousing compartment, in a position opposite to said window, saidconnections being arranged at opposed ends of said windows; saidcompartment housing an essentially U-shaped lamp having an essentiallyrectilinear central portion and two terminal portions with electrodesforming current leads by which said lamp is connected to said electricalconnections, said essentially rectilinear portion facing said window, areflector being provided adjacent said lamp in a direction away fromsaid window, said window being filled with a light guide, saidcompartment for housing the lamp being cooled by ducts carrying acooling fluid.
 14. The handpiece as claimed in claim 13, wherein saidlight guide is completely housed within a sealing cover of thehandpiece.
 15. A handpiece for treating a surface by means oflamp-emitted electromagnetic radiation, comprising: a pair of electricalconnections for the lamp and a compartment for housing a lamp, saidcompartment having an elongated window for the output of theelectromagnetic radiation generated by said lamp, wherein saidelectrical connections are placed side by side and are positioned on thesame side of the housing compartment, in a position opposite to saidwindow, said connections being arranged at opposed ends of said windows;said compartment being designed to house an essentially U-shaped lamphaving an essentially rectilinear central portion and two terminalportions with electrodes forming current leads by means of which saidlamp is connected to said electrical connections, said essentiallyrectilinear portion facing said window when the lamp is housed in saidcompartment; a grip portion connected to said compartment for housingthe lamp, said compartment for housing the lamp formed in a taperedportion of said grip portion, said lamp housing compartment beingtapered in shape and terminating with said output window.
 16. Ahandpiece for treating a surface by means of lamp-emittedelectromagnetic radiation, comprising: a pair of electrical connectionsfor the lamp and a compartment for housing a lamp, said compartmenthaving an elongated window with rectangular opening for the output ofthe electromagnetic radiation generated by said lamp, wherein saidelectrical connections are placed side by side and are positioned on thesame side of the housing compartment, in a position opposite to saidwindow, said connections being arranged at opposed ends of said windows;said compartment being designed to house an essentially U-shaped lamphaving an essentially rectilinear central portion and two terminalportions with electrodes forming current leads by means of which saidlamp is connected to said electrical connections, said essentiallyrectilinear portion facing said window when the lamp is housed in saidcompartment; said window being filled with a light guide; said taperedportion being delimited by a sealing cover provided with said windowfilled with said light guide, said cover pressing the light guide ontoan inner wall delimiting said compartment for housing the lamp; andducts for circulating cooling fluid, said ducts extending along atapered wall into said compartment housing said lamp.
 17. The handpieceas claimed in claim 16, wherein said cover has a housing in which thelight guide is completely contained.
 18. A handpiece for treating asurface by electromagnetic radiation, the handpiece comprising: agripping portion; a lamp housing compartment rigidly connected to saidgripping portion; ducts extending into said lamp housing compartment tocirculate a cooling fluid; a U-shaped flash lamp characterized by apulsed light source arranged in said lamp housing compartment, said lamphaving a substantially rectilinear central portion and two terminalportions; a pair of electrical connections for said lamp arranged insaid compartment; a window in said compartment for passingelectromagnetic radiation generated by said lamp, said electricalconnections and said window are designed and arranged such that saidsubstantially rectilinear central portion of said lamp faces said windowand extends substantially parallel to said window.
 19. The handpiece inaccordance with claim 18, further comprising: a cooling liquidcirculation system for cooling said lamp housing compartment.
 20. Thehandpiece in accordance with claim 18, wherein: said lamp housingcompartment has a tapered portion ending with said output window.
 21. Ahandpiece for treating a surface with electromagnetic radiation, thehandpiece comprising: a grip portion shaped to be gripped by a hand ofan operator applying the electromagnetic radiation to a patient; a lamphousing compartment connected to said grip portion, said lamp housingcompartment including an elongated window with rectangular opening forpassing electromagnetic radiation, said lamp housing compartment beingformed in a tapered portion of said grip portion, said lamp housingcompartment tapering in shape from said grip portion to said window; alamp characterized by a pulsed light source arranged in said lamphousing compartment, said lamp having a substantially rectilinearcentral portion facing said window and two terminal portions, saidterminal portions being bent away from said from said central portion ina direction away from said window and toward said grip portion, areflector being provided adjacent said lamp in said direction away fromsaid window; electrical connections arranged in one of said grip portionand said lamp housing portion, said electrical connections beingconnected to said terminal portions of said lamp, said electricalconnections being arranged on a side of said lamp which is diametricallyopposite said window, said lamp housing compartment being closed by saidwindow to radiate said lamp evenly on a patient's skin surface and aduct being provided between said lamp housing compartment and saidwindow.